BACKGROUND:The anatomic structures and kinetic characteristics are the bases to establish hand model, and the kinetic characteristics of hand are determined by the anatomic structure. So, numerous scholars have paid close attention to virtual hand models based on the anatomic structures of hand.OBJECTIVE: To construct visible hand model based on anatomic structure.DESIGN: Single sample trial.SETTING: Center Laboratory, Third Military Medical University of Chinese PLA.MATERIALS: This trial was carried out in the Center Laboratory, Third Military Medical University of Chinese PLA in October 2003. Two fresh adult hands, which involved wrist joint, provided by the Department of Anatomy, Third Military Medical University of Chinese PLA, were employed. The two hands had no organic damage by naked observation.METHODS: The specimens were embedded and mill-cut (mill-cut layer thinness 0.2 mm). Cannon (ESO 1OD) digital camera (6.3 million pixel) was used for image collection. Each image was 31.5 MB, Data of 1 200 images were obtained.Adobe Photoshop 7.0 software was used for image treatment and then two-dimensional cross-section images were collected. The bone, flexor tendon and the outline of hand was three-dimensionally reconstructed by using the software,which was developed by the Department of Computer Science and Technology,Tsinghua University and Institute of Computer Medicine, Department of Anatomy, Third Military Medical University of Chinese PLA.MATN OUTCOME MEASURES: Three-dimensional reconstruction of the bone, flexor tendon and outline of hand.RESULTS: ①The outline of hand: After being reconstructed, the outline, which consisted of all fingers and nails, was well displayed, and observed from many directions.② Three-dimensional reconstruction of the bone of hand: The reconstructed bones of hands involved digital bones, metacarpal bones, carpal bones and all joints, and they could be displayed solely or in groups with other reconstructed structures.③ Three-dimensional reconstruction of the flexor tendons of hand:Four superficial flexor tendons, four deep flexor tendons and one flexor pollex Iongus muscle tendon could be seen from the reconstructed images. All the flexor tendons went out together from the carpal canal and went through the palm, then spread out in fan-shape along the direction of each finger. ④ Three-dimensional reconstruction of the metacarpal fascial spaces: It could be observed from the reconstructed three-dimensional models that the proximal end of the thenar space was close, its distal end was open to the 1st web space, and the proximal end of the midpalmar fascial space was open to the posterior space of antebrachial flexor by carpal canal. Its distal end had three little spaces, which were open to the 2nd, 3rd and 4th web space, respectively.CONCLUSION: The visible hand model, which is preliminarily established, can precisely show the main anatomic structure of palm.

Aim To investigate radioprotective effects of platelet factor 4 (PF4) on hemopoiesis of mice after γ -ray irradiation and their mechanisms. Methods The mice were injected with PF4 twice at 6h intervals; and 20 h after the second injection they were given one irradiation of 7.5Gy 60Co γ -ray. 8d later the colony forming unit of granulocyte-macrophage (CFU-GM), colony forming of unit spleen (FU-S), number and DNA contents in bone marrow cells (BMCs) were examined by flow cytometry. Results 8d after irradiation, a significant difference was shown between DNA contents in BMCs and cell cycles of the PF4-injected mice and those of the irradiated mice (P∨ 0.01), whereas little difference was found between those of the irradiated mice and the controls (P∧ 0.05). Conclusion PF4 can obviously protect hemopoietic stem cells (HSCs) of mice from radiation injury and promote proliferation of HSCs after radiation.

BACKGROUND: The treatment of upper cervical spine disorders through a posterior pedicle fixation approach have been carried out in some domestic large hospitals, but this surgery is still considered as a difficulty of cervical spine surgery. In order to minimize the risk of surgery, the authors designed a program of individual operations, and combined with self-developed pedicle locating and directing speculum to determine precise intraoperative position of pedicle screws, and no report is found by searching related database in China.OBJECTIVE: To improve the one-time success rate of internal fixation screws, to investigate the biomechanical effect of the implant, to formulate a simple, practical, individual protocol for atiantoaxial pedicle screw-plate system based on related data. METHODS: A total of 31 patients were recruited from Department of Orthopaedics in the 251 Hospital of Chinese PLA, between January 2002 and September 2006. Under the guidance of self-made atlantoaxial locating and directing speculum, the entrance point and angle for screw insertion, as well as screw diameter and length were determined according to the results of X-ray and CT measurement. Atlas pedicle screw was inserted at left (19.93±1.32) mm, and right (19.16±1.3) mm; Atlas pedicle screw insertion angle to inside was left (23.72±2.09)°, and right (23.35±1.91)°; Atlas pedicle screw insertion angle to side of head was (9.00±1.20)°. Axis pedicle screw was inserted at left (13.14±0.82) mm, and right (13.85±0.79) mm; Axis pedicle screw insertion angle to inside was left (24.52±1.26)°, and right (20.42±1.42)°; Axis pedicle screw insertion angle to side of head was (25.00±3.00)°.RESULTS AND CONCLUSION: ①Totally 124 pedicle screws were implanted into 31 patients, and 122 screws were of one-time success. The precision rate was 98.39%. Two screws were secondly inserted because of cutting lateral cortical bone of pedicle for deviation of inward angle. ②Occipital neuralgia was found in 2 cases postoperatively and cured after one month of treatment;screws penetrated atlas left vertebral lateral wall in 2 cases, no spinal or vertebral artery injury was found. ③Radiographs showed that atlas was completely reduced in all patients, and apposition of dentoid process of axis fracture was good. CT films showed the screws a good location to the vertebrarterial spinal cord. ④The follow-up visit was averaged of 10.5 months. Bony fusion was found in all patients. No screw-plate breakage was found. No inflammatory or rejection reactions occurred.⑤By JOA scale, there were 16 cases of excellent, 12 cases of good, 2 cases of fine, and 1 case of poor. The excellent and good rate was 90%. It is suggested that the success rate of atlantoaxial pedicle screw-plate mplantation can be improved through a biomechanical angle.

Objective To evaluate the method and outcomes of radiocarpal joint reconstruction via nonvascularized and vascularized fibular bone graft after distal radius bone and joint defect.Methods Between November,1966 and March,2009,27 cases with distal radius bone and joint defect due to tumor en bolc excision (24 cases) or AO C3 type fractures (3 cases) were treated with nonvascularized or vascularized fibular bone graft.There were 9 males and 18 females.The mean age of these patients at the time of surgery was 27 years (rage from 16 to 67 years).There were 14 left sides and 12 right sides and 1 bilateral side.Nine cases with vascularized and 18 cases with nonvascularized fibular bone graft for radiocarpal joint reconstruction.The bone fixed with plate or/and k-wire.DASH scores,G/W wrist scores,PRWE scores were applied for writ function evaluation and the grasp power recovery rate and bone healing time was also compared during postoperative follow up.Results All 27 patients were followed with an average follow-up time being 9 years (range from 3.5 years to 44.0 years).The average length of fibular bone harvested was 10 cm for vascularized bone graft and 9 cm for nonvascularized.The all fibular bone was healed and the average healing time was 4.7 months (range from 3-8 months).No tumor recurrence or distance metastasis occurred during the follow-up.The average DASH scores was 7.97 (2.5-17.0),G/W scores of 24 patients ranged from 1 to 2,the wrist function result was excellent,account for 88.9％,and 3 cases from 3 to 7,function was good,account for 11.1％; the average grasp power recovery rat was 85.81％ (75％-104％); the average PRWE scores were 25.3(10.5-38.0).Comparison outcomes between the nonvascularized and vascularized fibular bone graft for radiocarpal wrist joint reconstruction,there was no significant statistics difference for bone healing time,DASH,G/W,PRWE scores and grasp power recovery rate (P ＞ 0.05).There were no other complications occurred except 3 patients had mild leg pain after long distance walking and 1 case fracture following patient's accident postoperative 11 years,and healed through conservative treatment.Conclusion The nonvascularized or vascularized fibular bone graft is an excellent choice and has less complication with maximal wrist function recovery for radiocarpal joint reconstruction following distal radius bone and joint defect due to all kinds of reasons,such as tumor en bloc excision,distal radius AOC3 type comminuted fracture.The vascularized fibular graft is recommended for larger than 12 cm bone graft.

BACKGROUND : After femoral neck fracture, incidences of ischemic necrosis and bone non-healing are closely related to biomechanical characteristics of internal fixation devices. Compression stress can improve fracture healing, tension force can delay fracture healing, and shear stress can inhibit fracture healing. How to relieve shear stress and expand compression stress is of significance for theories and clinical applications.OBJECTIVE: To compare the biomechanical characteristics of the two geometric configurations of three cannulated compression screws in the fixation for femoral neck fracture and to provide a theoretical foundation in the treatment of femoral neck fracture.DESIGN : Observational contrast study.SETTING: Department of Orthopaedics, the 251 Hospital of Chinese PLA; Department of Orthopaedics, the Third Hospital, Hebei Medical University.PARTICIPANTS: The experiment was carried out in the Hebei Orthopaedic Institute from November 2002 to March 2003. Five cadavers including 4 males and 1 female with similar bone mineral density (BMD) were provided by Department of Anatomy, Hebei Medical University. X-ray photographs proved that all the cadavers did not have rheumatism, tuberculosis, tumor, fracture or deformity.METHODS: Ten femurs were randomly divided into inverted and upright isosceles triangle with 5 in each group. Femur samples with femoral neck fracture were fixed with three cannulated screws and measured with the biomechanical machine (CSS-44020, made in Changchun Experimental Researching Institute, provided by Hebei Orthopaedics Institute). The compression strength, torsibility and the maximal vertical loading were compared between the two configurations of screws.MAIN OUTCOME MEASURES:①Displacement of femoral head at 600 N and 750 N during torsibility test; ②torque-moment at 2°and 4°during torsibility test;③load during maximal vertical loading test.CONCLUSION: The effect of three cannulated compression screws configured as an inverted isosceles triangle on the treatment of femoral neck fracture is superior to that of three cannulated compression screws as an upright isosceles triangle.

Teachers are principal parts in the innovation and implementation of teaching.Along with the deepening transformation of new medical teaching mode,higher demands have been set for the construction of teachership and for the education and training of teachers.The article gives an analysis on several issues that should be given attention to in the teacher training.